Compressor



rroamsys. 7

iiwmon. 050126: E. Rowers 97w 2 ShQets Sheet 1 MN I COHPRES SOR s. E.ROBERTS Dec. 3,- 1935. e. E. ROBERTS Re. 19,

' r cournssson Original Fi ed u l 26, 1932' 2 Shuts-Sheet 2 I INVENTOR.

ATTORNE "Man/ 05217 650262 E. Boner;

Reissued bca-3f Q 7 UNITED STATES I PATENT on-ice George'E. Roberts,Burbank, Calif., assign of one-fourth to Rudolph A. Rich and one-fourthto Forest 0. Rick, both of Rhinelander, Wis.

Original No. 1,931,207, dated October 17, 1933, Serial No. 613,735, May26, 1932. Application for reissue August 13, 1934, Serial No. 739,707

3 Claims- (Cl. 103-139) This invention relates to rotary compressors,rotor. To produce a highly effective fluid seal and while it is designedmore especially for use in between the stator, the rotor and the vanes,it is systems of mechanical refrigeration. it canalso intended that thevanes freely move axially of be advantageously employed in hydraulictransthe rotor and relatively to the cam side of the missions andwherever it may be desired to cirstator so that their adJacent fluidsealing edges 5 culate or compress fluid in a simple and emcient can beeffectively advanced against the coasting manner. face of the statorwall.

One of the objects of the invention is to pro- Wlth the foregoing andother objects in view, vide a rotary compressor made up of the miniwhichwill appear as the description proceeds, l0 mum number of parts, itbeing possible to readthe invention resides in the combination and arilyassemble them. rangement of parts and in the details of con- Anotherobject is m provide compresfor of struction hereinafter described andclaimed, it this type which will not easily get out of order, beingunderstood that changes may be made in and can be made at low cost. Ithe precise embodiment of the invention herein A still further object isto provide a compressor disclosed within the scope of what is claimedwith- 15 which will operate eiliciently at a comparatively out departingfrom the spirit of the invention. slow speed, it being possible toobtain efiicient In the accompanying drawings, the preferred resultsfrom a six-inch rotor operating 'as low form of the invention has beenshown. as 60 R. P. M. This is accomplished by increas- In said drawings,:0 ing to a maximum the sealing areas of the co- Figure l is a centrallongitudinal section acting wallsor worldng faces of the stator andthrough the compressor showing one of the imthe rotor without im osingexcess frictional loads peller vanes broken away at the working spacethereon and by constructing the rotor to func- 'of the stator;

tion as an inertia mass to counteract to an ap- Figure 2 is a section online 2-2 of Figure 1; pr'eciable extent the retarding effect of fric-Figure 3 is a section on line 3-3 of Figure 1; 25

tional loads or drags imposed upon said areas by Figure 4 is a sectionon line 4-4 of Figure 3;

the impeller vanes and other frictional factors. Figure 5 is a viewpartly in edge elevation of the I have discovered that by making theface width compressor with parts of the stator in section; 'of the rotorrelatively broad in proportion to the Figure 6 is a perspective view ofone head of the so outside diameter of therefor and by iiiterposingstator:

said rotor between two fixed walls of the stator Figure '7 is aperspective view of the rotor; housing so that the side faces of therotor are Figure 8 is a perspective view of the body porsubsta'ntiallyin cons tcontact with the respection of the stator showing the otherhead; tive inner faces of said fixed walls, the capacity Figure 9 is aperspective view of the rotor lookarea of the working chamber of thecompressor nc toward t Opp te side thereof from that 3 remains constant,and in consequence thereof Shown n F gu uniform volumetric emciency ismaintained. A F gu e 10 is a perspective view of one of the compressorof this class is purposely designed to impeller vanes. i give constantvolumes per revolution of the rotor. er ng to the figures by charactersof refer- 40 To obtain a reduced flow, it is to be understood n Idesignates a stator dy w h s p ef r- 40 that this can be accomplished byreducing th ably cylindrical. One end of the body is closed speed of therotor. However, at any fixed speed by a head 2 which can be integraltherewith and of the rotor, the discharge capacity of the comprovides a.bearing 2a for the shaft 3 Of the rotor. pressor remains constant due tothe fact that the The other end of the body has an annular flange rotoris closely interposed between said fixed I, to which a removable head 5is detachably se- 5 walls of the stator and, therefore, cannot movecured by means of bolts or other suitable devices, axially. The capacityremains constantalso beindicated at 6. This head is formed with anincause the width of the compressing space is not wardly offset portion1 which forms an annular variable at any period in the rotation of saidabutment, the ends 8 of which are inclined toward 5o rotor between thefluid'intake side of thestator the flat intermediate surface 9 of saidportion 1, and the discharge side thereof. The intended the latter andsaid ends 8 representing approxihigh volumetric emclency from a six-inchrotor mately one-half the face area of that part of at an operatingspeed as low-as 60 R. P. M. is the head 5 which confronts the inner faceof further made possible because of the manner, in head 2. One or moreports l0 can open through which the impeller vanes are mounted upon theeach inclined or deflecting end 8 of the portion I, 66

and these can be in communication with pipes ll, one of which canconstitute an inlet for fluid to be compressed while the otherconstitutes the outlet for the compressed fluid.

The removable head 5 has a socket l2 constituting an end bearing, thesame disposed in axial alinement with the aforementioned bearing id forthe shaft 3. Secured to this shaft between the heads 2 and 5 is a rotorl3, the .flat face l3a of which fits snugly against the fiat face 9 ofthe portion. 1. The hub 14 has a portion Ila which extends from saidsurface I3a of the rotor, the fiat face Nb of which abuts against theinner fiat face So of head 5, its periphery having a tight working fitagainst the inner arcuate surface Ia of said portion 1.

The rotor is provided with diametrically opposite slots l5 extendingtherethrough from the periphery of the rotor to a point inwardly of theperiphery of the main body portion of the hub II, as shown in Figures 2and 9. These slots are intersectedby a deep circular channel I6 formedin that face, of the rotor nearest the head 2. This ,channel isconcentric with the rotor, provides a seat for a coiled spring l1 whichbears at one end against the inner flat face 21) of head 2. and normallythrusts at its outerend against the inner end wall of the channel.Slidable within each of the slots I5 is a rectangular plate l8constituting an impeller yane. Each blade extends from the inner wall ofits slot outwardly to the periphery of the rotor and that end of theblade or vane nearest the head 2 is recessed at [9, so as to straddlethe adjacent convolutions of the spring I]. Thus the one spring servesto hold both vanes normally pressed toward head 5. Consequently, as therotor is operated, each vane will successively ride over one inclinedterminal 9 of the abutment-forming portion 1, so as to place the springunder compression, then along the flat surface 9 of said portion, atwhich time the spring is further compressed, and subsequently down theother inclined'terminal 9 and along the sur-' face So of the head 5, thelatter representing the other half of the face area of said part of thehead which confronts the aforementioned inner face of head 2. Duringthis movement of each vane, fluid in advance thereof will be expelledthrough the ports 10 first reached by the vane, and as the vane movesaway from the other terminal of the abutment portion the fluid to becompressed will be sucked through the port or ports in said terminal andpositioned behind the vane. By providing two vanes, as shown, acontinuous stream of fluid can be delivered under pressure from thestator. It has been found, in practice, that a compressor constructed asdescribed can be made at low cost and will operate emciently at a lowspeed and without overheating. Importance .is attached to the fact thatthe compressor is made up of very few parts and,

consequently, will seldom require repairs. All of the parts are readilyaccessible by removing the head 5, and in the event of excessive wear ofthe vanes, those parts can be easily removed without requiring theservices of a skilled mechanic. a

. It will be appreciated, on reference to Figures 1, 7, 6 and 8, thatthe flat annular face 9 of the abutment portion I is disposed inparallel relation to the flat face lie of the rotor l3, and that theflat face lleand the flat face He at the opposite side of the rotor areparallel to the inner flat face In of the head 2. the said faces lie andNe beingin the same vertical plane with each other. Upon particularreference to Figures 1 and 5, it will be observed that the peripheralface width of the rotor is co-extensive with the distance represented bya straight line from the face 9-to the face 2a and parallel to thehorizontal axis of the rotor. It follows therefrom that said face I311will constantly operate against the face 9, whereby to provide aneffective fluid seal there-..

between and thus prevent fluid leakage between the portion of increasedwidth of the working chamber of the stator and the portion of lesserwidth of said chamber. The portion of increased width will be hereinreferred to as the suction and pressure space.' The portion of lesserwidth which is wholly occupied by the wall thickness of the rotor, willhereinafter be referred to as the fluid-sealing space. It will also beobserved that. during operation of the rotor and because of the mannerin which the vanes are mounted, the inner transverse edges of the vaneswill bear tightly against the smooth peripheral surface of the hubportion Ma, as will be appreciated on reference to Figure 1, thussealing the space therebetween to. prevent leakage of fluidtherethrough. The extension Ha of the hub is of smaller diameter thanthat of the main body portion of the hub,

and it will be appreciated, upon again referring to Figure 1. that thegrooves i5 formed in said main body portion terminate at a pointinwardly of the inner wall of the channel i6 ,'thus leaving. theextension Hla smooth as aforestated and as is necessary to a propersealing of the space between same and the adjacent edge of the impeller.

Again referring to Figure 1, it will be observed that the left hand endof the lower one of the vanes l9 therein illustrated has been yieldinglyadvanced by the spring IT to an effective fluidcompressing positionwhere its radial edge nearest the head 5 is in flat sealed contact withthe large-area flat surface 50. of said head 5. The flat surface Nb ofthe hub is in fluid-sealed contact 'with the same flat surface 5a, whereit is partly embraced by. the bearing surface la. In consequence of theemployment of the means aforestated for sealing the vane, it will befurther noted that on movement of the lower vane to the position justdescribed, an effective seal is also established between the vane, theface 90. and

the inner wall of the stator, so as to prevent leakage of fluid pastthese lines. The seal thus formed and the seal formed in a somewhatsimilar manner by the companion vane of the rotor,

and the fact that the face width of the rotor is equal to the shortestwidth of the working space which separates the head I and face 9 fromeach other, and is broad relatively to the outside diameter of therotor, are all contributing factors that co-ac't to provide a rotorconstruction in which all contact areas are well sealed. The form of therotor is also such as to give it an inertia value sufflcient tocounteract, to a considerable extent, the retarding frictional loads anddrags imposed upon the contact areas. The construction is, further, suchthat the capacity area of the working chamber of the compressor willremain constant at all speeds so that uniform volumetric emciency ismaintained at all times. The leakage line that would be expected to giverise to pressure losses in a compressor of this type would be bounded bythe surface 9a, the confronting radial edge of the impeller vane thatrides thereover, the outer edge of the same vane from a point'at thesurface in to the flat face Ila of the rotor, and the inner edge of thevane where it that ts sides with time co-actins stator chine walls, itfollows that the rotor held against movement axially of the stator. Inview thereof, the

and give rise to losses in pressure and volumetric displacement would beat the face 9 and the adiacent radial edge of the impeller vanes whichride thereover.. As the rotor and stator are perfectly sealed at thislast named point, no fluid can pass from the suction and pressure spaceto the aforementioned fluid sealing space, which is a furthercontributing factor toward maintaining a very high measure of efficiencyand avoidingfluid pressure lossm.

I have stated that-the distance from the face 9 -to-thefaceIbisequaltothe facewidth of the rotor. It follows that the vanes llmust, therefore, be co-extensive with the face width of the rotor sothat they will be wholly containedwithin the slots of the rotor, whenthe vanes are acted upon by said face 9. width of the vane II isco-extensive, with the face width of the face 9 on any line passingacross saidfacelradiallyoftheaxisoftherotor. This face l and the flatside l3a of the rotor.

The faces in and 9 are parallel'to each other, and they are also indifferent vertical planes, so

'as to allow for the intended maximum extent of movement of the vanesaxially of the rotor and into sealed engagement with the face is of thehead I. The low ends of the inclines I are in substantial alinement witheach other and offset from a line drawn through the axis of rotation ofthe rotor, so that the vanes which are diametrically lines parallel toall surfaces thereof, which are radial to the axis of the rotor. Thislsanorder that the radial edges of the vanes which confront the head 5will evenly contact with the inclines It follows also that the insures aproper sealing of the space between the opposite each other willapproach the inclines on large extent against leakage, between the vanesand the co-acting contact surfaces of the head i. 5

Although this device has been described 98 F marily-for use as acompressor, it is also to be understoodthatitcanbeusedasaon unit.

What is claimed is: i0"

1. In a rotary pump. the, combination with at stator; a rotor; axiallymovable vanes on the rotor; and means on the stator for moving the vanesaxially in one direction; of resilient means common to all the vanes forexerting a constant 15 force against them to move same axially in theopposite direction; and means for operatively mounting the resilientmeans. within the rotor. 2. In a rotary machine of the class described,a stator having a rotor chamber provided with a U concentrically.mounted rotor and said rotor having axially reciprocal vanes; cam meansfor moving the vanes axially in.one direction; and a coil spring mountedin the rotor concentric to the axis thereof and engaging all of thevanes 35 to move same in an opposite direction and against said cammeans.

3. In a rotary machine of the class described, a stator having acylindrical bore and oppositely disposed heads, one of said heads havinga concentric abutment on its imi face, said abutment having terminal camfaces; a plurality of axially movable vanes carried by the rotor andadapted to co-act with said abutment, the width of each vane beingsubstantially equal to the axial distance between the intermediateportion of the abutment and the other head, the cam faces coacting withthe vanes to respectively cause and enable the vanes to approach andride over the intermediate portion of the abutment and then leave samein rotation of the rotor; and a coiled spring mounted in the rotorconcentrically thereof and provided with portions engasinz the vanes toconstantly exert a yielding pressure thereagainst axially of said rotorand toward said r abutment.

GEORGE E. ROBERTS.

